Leak mitigation for pressurized bi-directional systems

ABSTRACT

A bi-directional pressurized system with devices for and configured to mitigate issues associated with leak and creep phenomena at various stages throughout the system, including valves and controls to distribute a leaked amount of fluid prior to delivery to a pressure-sensitive destination and a pressure relief valve to bring an initial pressure within an acceptable range for distribution to reach a target pressure is disclosed. A startup method for mitigating leakage of the system during a rest phase, including selectively reducing the initial pressure upstream of a pressure-sensitive destination, is disclosed.

RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.12/618,606, filed on Nov. 13, 2009 now U.S. Pat. No. 8,215,331. Theentire disclosure of application Ser. No. 12/618,606 is incorporatedherein by reference, as if fully set forth herein.

BACKGROUND 1. Field

The present disclosure relates to pressurized systems for storing andproviding fluids. In particular, the present disclosure relates tomitigation of leaks and creep phenomena in pressurized gas systems.

SUMMARY

According to aspects of at least one exemplary implementation, a systemfor mitigating leaks is disclosed, comprising: a fluid source; aninjector; a regulator disposed between the fluid source and theinjector; a system isolation valve disposed between the regulator andthe injector; a first line connecting the fluid source to the regulator;a second line connecting the regulator to the system isolation valve,the second line having a second volume; and a third line connecting thesystem isolation valve to the injector, the third line having a thirdvolume. The combined second volume and third volume may be configured toreduce an initial pressure of a fluid in the first line to adistribution pressure when the system isolation valve is opened. Thesystem isolation valve may be configured to open if the distributionpressure is equal to a target pressure for the injector.

According to aspects of at least one exemplary implementation, thesystem may further comprise a pressure relief valve configured to ventthe fluid in the second line if the distribution pressure would begreater than the target pressure. The pressure relief valve may befurther configured to reduce the pressure in the second line to notexceed a release pressure. The fluid source may be a storage tank havinga tank valve. The fluid may be pure hydrogen. The injector may bedisposed between the second line and a fuel cell. According to aspectsof at least one exemplary implementation, the system may furthercomprise a low pressure sensor configured to sense the pressure in thesecond line.

According to aspects of at least one exemplary implementation, a startupmethod is disclosed for a pressurized system having a first linedisposed between a tank valve of a storage tank and a regulator,comprising: sensing an initial pressure of a fluid in a second linehaving a second volume and disposed between a regulator and a systemisolation valve, wherein the system isolation valve selectively connectsthe second line with a third line having a third volume and beingdisposed between the system isolation valve and an injector; calculatinga distribution pressure; and if the distribution pressure is less thanor equal to a target pressure, opening the system isolation valve,whereby the fluid in the second line is distributed across the secondline and the third line and delivered to the injector at the targetpressure.

According to aspects of at least one exemplary implementation, thestartup method may further comprise: if the distribution pressure isgreater than the target pressure, opening a bleed valve connected to thesecond line, whereby the fluid in the second line is at least partiallyvented. According to aspects of at least one exemplary implementation,the startup method may further comprise: opening the tank valve.

According to aspects of at least one exemplary implementation, a startupmethod is disclosed for mitigating leaks in a pressurized system havinga first line disposed between a tank valve of a storage tank and aregulator, comprising: sensing an initial pressure of a fluid in asecond line having a second volume and disposed between a regulator anda system isolation valve, wherein the system isolation valve selectivelyconnects the second line with a third line having a third volume andbeing disposed between the system isolation valve and an injector; ifthe pressure in the second line is greater than a release pressure,connecting the second line to a pressure relief valve, whereby thepressure in the second line is reduced to the release pressure; and ifthe pressure in the second line is less than or equal to the releasepressure, opening the system isolation valve, whereby the fluid in thesecond line is distributed across the second line and the third line anddelivered to the injector at a target pressure.

According to aspects of at least one exemplary implementation,connecting the second line to a pressure relief valve may furthercomprise: opening a bleed valve. The connecting step may furthercomprise: closing the bleed when the pressure in the second line issubstantially equal to the release pressure. A pressure differentialacross the tank valve may be reduced prior to opening the tank valve. Apressure differential across the system isolation valve may be reducedprior to opening the system isolation valve.

DRAWINGS

The above-mentioned features and objects of the present disclosure willbecome more apparent with reference to the following description takenin conjunction with the accompanying drawings wherein like referencenumerals denote like elements and in which:

FIG. 1 shows a schematic diagram of a traditional bi-directional system;

FIG. 2 shows a schematic diagram of a storage tank with an active ontank device;

FIG. 3 shows a schematic diagram of a bi-directional pressurized system;

FIG. 4 shows a flow chart of a startup process for a pressurized system;

FIG. 5 shows a schematic diagram of a pressurized system; and

FIG. 6 shows a flow chart of a startup process for a pressurized system.

DETAILED DESCRIPTION

Traditionally, regulators are not effective as sealing devices. Aregulator's function is to control its downstream pressure in a flowcondition. At no flow, the upstream pressure will gradually leak throughthe internal seat, resulting in a decrease of upstream pressure and anincrease of downstream pressure. This phenomenon is known as “creep.”Furthermore, regulators having more precise output regulation (e.g.,+/−0.1 Mpa) make the creep phenomena more significant, particularlywhere additional components downstream of a regulator require pressurevariation to be within a precise range for proper operation.

FIG. 1 shows a traditional bi-directional mechanization for a hydrogenstorage system. Fill line 20 provides a fluid (gas or liquid) throughcheck valve 22 to a point that diverts into two directions alongspending line 24: one direction to storage tank 30 and another directionto regulator 40. This bi-directional mechanization has multipleadvantages. For example, redundant tubing is avoided inasmuch asportions of spending line 24 are the same as portions of fill line 20.Thus, this mechanization provides minimal tubing connections and minimaljoints for external leak.

According to aspects of at least one exemplary implementation, storagetank 30 is provided with appropriate control and regulation devices tomanage the flow and conditions of fluid of storage tank 30. For example,tank valve 32 may be provided at the entrance and exit line of storagetank 30. Tank valve 32 may be a solenoid valve, a manual valve, an airactivated valve, or other valve to selectively control flow in and outof storage tank 30. According to aspects of at least one exemplaryimplementation, tank valve 32 may be part of a broader system formanaging storage tank 30. For example, as shown in FIG. 2, active ontank device 31 of storage tank 30 may include temperature sensor 34,pressure sensor 33, excess flow valve 35, filter 36, manual valve 37,tank valve 32, thermal pressure relief device 38, defueling valve 39,orifice 41, and appropriate inlets and outlets.

According to aspects of at least one exemplary implementation, regulator40 may be provided between storage tank 30 and the destination, such asinjector 90 or other component that receives a flow of the fluid fromstorage tank 30, as shown in FIG. 1. For example, single stage regulator40 may be provided. Regulator 40 may be configured to reduce anyupstream pressure from storage tank 30 to within an acceptable rangewith tolerances (i.e., a target pressure). For example, regulator 40 maybe configured to reduce the downstream pressure to 0.9 MPa (g)+/−0.1.The acceptable range with tolerances may correspond to limitationsimposed by an intermediate or ultimate destination of the fluid. One ormore devices at or downstream of a destination of a system may besensitive to pressure. For example, regulator 40 may be configured tomanage downstream pressure to injector 90, which may only be configuredto receive fluid within certain pressure conditions without sustainingundesirable damage. Without adequate accommodation, leakage from tankvalve 32 or regulator 40 may cause an undesirable pressure load to bedelivered to the destination.

According to aspects of at least one exemplary implementation, devicesand configurations for managing the downstream pressure to thedestination may be managed to mitigate leaks at tank valve 32 orregulator 40 stage of the system.

According to aspects of at least one exemplary implementation, abi-directional system is shown in FIG. 3. System isolation valve 50 maybe provided between regulator 40 and the destination (e.g., injector90), as shown in FIG. 3. System isolation valve 50 may be a solenoidvalve that can be open at very low electrical power (i.e., because thepressure load is as low as 0.9 Mpa (g) nominal). Upon initiation of thesystem, system isolation valve 50 may open and provide its upstream flowfrom regulator 40 to the destination.

According to aspects of at least one exemplary implementation, creep atregulator 40 will provide an initially excessive upstream pressure tosystem isolation valve 50. For example, first line 51 may be defined asthe connection between tank valve 32 and regulator 40. Second line 52may be defined as the connection between regulator 40 and systemisolation valve 50. Creep at regulator 40 occurring while tank valve 32and system isolation valve 50 are closed will eventually cause thepressure between in first line 51 (upstream to regulator 40) to balancewith the pressure in second line 52 (downstream to regulator 40). Thismay present an excessive pressure condition to the destination whensystem isolation valve 50 is opened. If system isolation valve 50 opens,downstream injector 90 will receive higher pressure impulse. Such a highpressure impulse may cause injector 90 to leak, which may beparticularly dangerous if the fluid leaked is volatile. Moreover, theoperation life of injector 90 may be shortened due to these highpressure conditions. Furthermore, system isolation valve 50 and injector90 would require more power to overcome the increase pressuredifferential due to regulator creep.

According to aspects of at least one exemplary implementation, avolumetric solution is provided to provide an acceptable pressure to thedestination of a system, even after an occurrence of regulator creep.This solution is based on the isothermal balance of the fluid.

According to aspects of at least one exemplary implementation, firstline 51 is provided between tank valve 32 and regulator 40. First line51 has a first volume (V₁) and first pressure (P₁) therein. According toaspects of at least one exemplary implementation, second line 52 isprovided between regulator 40 and system isolation valve 50. Second line52 has a second volume (V₂) and second pressure (P₂) therein. Accordingto aspects of at least one exemplary implementation, third line 53 isprovided between system isolation valve 50 and injector 90 (or otherdestination device). Third line 53 has a third volume (V₃) and thirdpressure (P₃) therein.

According to aspects of at least one exemplary implementation, a targetpressure (P_(T)) may be defined as an acceptable pressure to be providedto injector 90. According to aspects of at least one exemplaryimplementation, the system has an initial state at or before the timesystem isolation valve 50 is opened. In the initial state, the secondpressure results from the existence of any regulator creep leading up tothe time of the initial state. The third pressure may be equal to orsubstantially equal to zero, because prior cycles would deplete theamount of fluid in third line 53 after system isolation valve 50 isclosed.

According to aspects of at least one exemplary implementation, whensystem isolation valve 50 is opened, the fluid in second line 52 will bedistributed across second line 52 and third line 53. Accordingly, adistribution pressure (P_(D)) may be defined as the pressure resultingfrom the substantially even distribution of the fluid in second line 52across the combined volume of second line 52 and third line 53 (V₂+V₃)at the time system isolation valve 50 is opened.

According to Boyle's law, pressure multiplied by volume and divided bytemperature in the first state will be equal to pressure multiplied byvolume and divided by temperature in the second state. This may beexpressed as:(P _(A) *V _(A))/T _(A)=(P _(B) *V _(B))/T _(B)  (Formula 1).

Where temperature remains substantially constant across both states,this reduces to:(P _(A) *V _(A))=(P _(B) *V _(B))  (Formula 2).

Thus, the pressure and volumes of a system during a state prior to theopening of system isolation valve 50 as compared to a state afteropening system isolation valve 50 may be expressed as:(P ₂ *V ₂)+(P ₃ *V ₃)=P _(D)*(V ₂ +V ₃)  (Formula 3).

Where the third pressure is equal to zero, this reduces to:(P ₂ *V ₂)=P _(D)*(V ₂ +V ₃)  (Formula 4).

To determine what the distributed pressure will be once system isolationvalve 50 is opened, Formula 4 may be rearranged and expressed as:P _(D)=(P ₂ *V ₂)/(V ₂ +V ₃)  (Formula 5).

According to aspects of at least one exemplary implementation, thesystem may be configured with known dimensions and parameters.Furthermore, the pressure in second line 52 may be measured by lowpressure sensor 42 located at second line 52. The known dimensions ofthe system and the measured pressure allow a distribution pressure to becalculated according to Formula 5.

According to aspects of at least one exemplary implementation, a startupphase as shown in FIG. 4 may be performed. Tank valve 32 and systemisolation valve 50 may be closed while the system is at rest in a restphase (operation 200). During this rest phase, the pressure in secondline 52 may increase due to regulator creep, but the pressure may becontained while system isolation valve 50 is closed. When a startupcommand is received, a startup phase may be initiated (operation 202).The pressure in second line 52 may be measured (e.g., by a low pressuresensor 42 (operation 204). With the measured pressure in second line 52and know values for the volumes of second line 52 and third line 53, adistribution pressure may be calculated, for example with Formula 5(operation 206). If the distribution pressure exceeds the targetpressure, then system isolation valve 50 may remain closed untilcorrective measures are taken (operation 208). A warning or otherindication may be sent to an operator or another system (operation 210).If the distribution pressure does not exceed the target pressure, thentank valve 32 and system isolation valve 50 may be opened (operations212 and 214). While fluid flows from storage tank 30 to injector 90, thesystem may maintain a steady state phase of operation. When a shutdowncommand is received, at least one of system isolation valve 50 and tankvalve 32 may be closed, if needed. (operations 216, 218, and 220).

According to aspects of at least one exemplary implementation, abi-directional system is shown in FIG. 5. Devices for relievingexcessive pressure may be provided. For example, as shown in FIG. 5,pressure relief valve 60 may be provided in fluid communication withsecond line 52. Pressure relief valve 60 may be a pressure responsivevalve, such as a valve that only conducts fluid when its upstreampressure reaches a certain threshold. The pressure threshold foractivation of pressure relief valve 60 is disclosed further herein,according to aspects of at least one exemplary implementation.

According to aspects of at least one exemplary implementation, systemisolation valve 50 and pressure relief valve 60 may operate together tomitigate pressure of the system. The activation pressure of pressurerelief valve 60 may be the pressure at which a calculated distributionpressure exceeds the target pressure of the destination device. Forexample, where the distribution of the fluid in second line 52 acrosssecond line 52 and third line 53 by opening system isolation valve 50 isstill insufficient to achieve the target pressure, then it can be saidthat the hypothetical distribution pressure is greater than the targetpressure. Pressure relief valve 60 may be configured to become activatedunder such conditions so that the pressure in second line 52 is reducedand the hypothetical distribution pressure is equal to or less than thetarget pressure.

According to aspects of at least one exemplary implementation, thevolumes of second line 52 and first line 51 may be selected tocorrespond to the activation pressure of pressure relief valve 60. Thisis the scenario in which the distribution pressure is the targetpressure, thus Formula 3 may be rearranged and expressed as:V ₃ /V ₂=(P _(P) −P ₂)/(P ₃ −P _(D))  (Formula 6).

According to aspects of at least one exemplary implementation, thepressure at which pressure relief valve 60 becomes activated may bedefined as the release pressure (P_(R)). The release pressure maycorrespond to the pressure in second line 52 while system isolationvalve 50 is closed, at which pressure the calculated distributionpressure would equal the target pressure. The release pressure may bedetermined and adjusted based on physical characteristics of pressurerelief valve 60. With this configuration, pressure relief valve 60 mayreduce the pressure in second line 52 such that the distributionpressure does not exceed the target pressure when system isolation valve50 is opened. With this, Formula 6 may be expressed as:V ₃ /V ₂=(P _(D) −P _(R))/(P ₃ −P _(D))  (Formula 7).

For example, pressure relief valve 60 may be configured to becomeactivated at P_(R)=1.6 Mpa(g), as measured in second line 52; the targetpressure desired for the distribution pressure to achieve may beP_(p)=0.9 Mpa(g); and the pressure in third line 53 may be P₃=0 whilesystem isolation valve 50 is closed. Under these conditions, the ratioof V₃/V₂ is calculated as 0.77 based on Formula 7. Thus, with secondline 52 and third line 53 having this ratio, pressures in second line 52exceeding 1.6 Mpa(g) will be released through pressure relief valve 60.Furthermore, pressures in second line 52 not exceeding 1.6 Mpa(g) willbe distributed across second line 52 and third line 53 when systemisolation valve 50 opens, and the distribution pressure will not exceedthe target pressure. In this way, pressure relief valve 60 and systemisolation valve 50 may operate together to ensure that the pressure tothe destination device does not exceed the target pressure.

According to aspects of at least one exemplary implementation, forautomatic operation, bleed valve 62 may be provided upstream of pressurerelief valve 60 or otherwise disposed between regulator 40 and pressurerelief valve 60. Bleed valve 62 may be a solenoid valve, manual valve,or other valve having “open” and “closed” states. In some applications,particularly in a vehicle with tight spaces, a manual valve may be lessdesirable because of the tight space; thus other valves, such as asolenoid valve, may be provided. According to aspects of at least oneexemplary implementation, bleed valve 62 may address issues relating tocontinual leakage through regulator 40 and release by pressure reliefvalve 60. For example, while system isolation valve 50 is closed,regulator 40 may experience creep there through. Where pressure reliefvalve 60 is provided, the pressure in second line 52 may be constantlyreduced to the release pressure.

According to aspects of at least one exemplary implementation, releaseof fluid through pressure relief valve 60 may be continual, planned,programmed, scheduled, controlled, variable, or otherwise configurable.In some instances, some fluids may be flammable and introduce a risk offire. The pressure in first line 51 may be reduced to the releasepressure if pressure relief valve 60 is permitted to operatecontinually. Where the release pressure is low relative to the pressurein storage tank 30, this causes a high differential across tank valve32, thereby increasing the energy requirement for opening tank valve 32.Furthermore, the fluid may be vented through pressure relief valve 60 toan unrecoverable state, such as into the atmosphere or surroundingenvironment. Where the fluid is a fuel, this decreases fuel efficiency.

According to aspects of at least one exemplary implementation, a startupphase as shown in FIG. 6 may be performed. Bleed valve 62 may be closedwhile system isolation valve 50 is closed and the system is at rest in arest phase (operation 300). During this rest phase, the pressure insecond line 52 may increase due to regulator creep, but the pressure maybe contained while system isolation valve 50 and bleed valve 62 areclosed. When a startup command is received, a startup phase may beinitiated (operation 302). The pressure in second line 52 may bemeasured (e.g., by a low pressure sensor 42) (operation 304). If thepressure in second line 52 exceeds the release pressure, bleed valve 62may be opened prior to system isolation valve 50, whereby the pressurein second line 52 is reduced to the release pressure by pressure reliefvalve 60 (operations 306 and 308). Low pressure sensor 42 may verifythat second line 52 has achieved the release pressure. When the pressurein second line 52 does not exceed the release pressure, one or more ofthe following may be performed: closing bleed valve 62, opening tankvalve 32, and opening system isolation valve 50 (operations 310, 312,and 314). While fluid flows from storage tank 30 to injector 90, thesystem may maintain a steady state phase of operation. When a shutdowncommand is received, at least one of system isolation valve 50, tankvalve 32, and bleed valve 62 may be closed, if needed (operations 316,318, and 320).

According to aspects of at least one exemplary implementation,maintaining bleed valve 62 in a closed state during a rest phase reducesthe amount of fluid that may be lost if pressure relief valve 60 isactive during a rest phase. Without bleed valve 62, tank valve 32 andregulator 40 may both leak, whereby the fluid in storage tank 30 maycontinuously feed to first line 51 and second line 52. Given sufficienttime, storage tank 30 may entirely empty through pressure relief valve60. Regulator 40 may better maintain a seal to substantially orcompletely limit creep where the downstream pressure is high. Wherebleed valve 62 maintains any pressure within second line 52, regulator40 may experience limited and improved creep phenomena. The fluidmaintained in at least second line 52 may be preserved for later use bythe system, rather than lost to unintended leakage. Furthermore, therelease of fluid during a startup phase in excess of the releasepressure occurs within a known period of time and location, therebyallowing the system or user to make adequate accommodations.

According to aspects of at least one exemplary implementation, theenergy requirement for opening tank valve 32 is reduced. For example,the pressure in first line 51 is maintained by preventing pressurerelief valve 60 to vent the fluid leaked via regulator creep. Where thevolume of first line 51 is large in comparison to the volume of secondline 52, the leak of fluid via regulator creep may not significantlyreduce the pressure in first line 51 as long as second line 52 iscontained by system isolation valve 50 and bleed valve 62. Thus, theenergy requirement for opening tank valve 32 may be reduced because thepressure downstream (i.e., in first line 51) of tank valve 32 issubstantially similar to the pressure upstream (i.e., from storage tank30).

According to aspects of at least one exemplary implementation, theenergy requirement for opening system isolation valve 50 is alsoreduced. Because the pressure in second line 52 may be reduced to therelease pressure, as disclosed herein, the pressure upstream of systemisolation valve 50 (i.e., in second line 52) is brought closer to thepressure downstream of system isolation valve 50 (i.e., in third line53, which pressure may be zero).

According to aspects of at least one exemplary implementation, systemsand methods of the present disclosure may mitigate issues relating toleak of both regulator 40 and tank valve 32. As disclosed herein, whensystem isolation valve 50 and bleed valve 62 are closed, the fluidwithin second line 52 may be contained. Thus, undesirable loss throughpressure relief valve 60 during a rest phase may be avoided even whereboth regulator 40 and tank valve 32 leak the fluid from storage tank 30into second line 52.

According to aspects of at least one exemplary implementation, reducingthe energy requirements during operation of one or more valves of asystem may improve energy efficiency of the system. Furthermore,reducing creep resistance requirements of one or more regulators mayimprove cost efficiency by allowing implementation of devices that arenot entirely creep resistant.

According to aspects of at least one exemplary implementation, bleedvalve 62 may be configured to be capable of opening under a maximumdifferential pressure occurring within the system. For example, bleedvalve 62 may be capable of opening at a differential equal to a maximumfill pressure of storage tank 30. Bleed valve 62 may be provided with acurrent drive as needed to operate under such conditions.

According to aspects of at least one exemplary implementation, systemisolation valve 50 may be configured to selectively contain at leastmaximum upstream pressure corresponding to the maximum pressureoccurring within the system. For example, system isolation valve 50 maybe capable of containing an upstream pressure equal to a maximum fillpressure of storage tank 30. System isolation valve 50 may further beconfigured to open at the release pressure.

According to aspects of at least one exemplary implementation, pressuresensors of the system, such as high pressure sensor 33 or low pressuresensor 42, may be configured to operate and sustain the maximum pressureoccurring with the system (e.g., a maximum fill pressure of storage tank30).

According to aspects of at least one exemplary implementation, adequatecontrol systems and devices may be provided in connection with relevantcomponents to monitor the system, control operation thereof, andinterface with a user or other systems. Such control systems may store,process, and communicate operation parameters, commands, data, andinformation relating to the system.

According to aspects of at least one exemplary implementation, any givendevice or component of the present disclosure may be provided inplurality through the system. For example, multiple valves, etc. may beprovided in series or parallel to provide customizable results. Byfurther example, multiple storage tanks 30 may be provided and connectedto a common line leading to a destination, as shown in Appendix A, theentirety of which is incorporated by reference, as if fully set forthherein.

According to aspects of at least one exemplary implementation, wherepressures are disclosed herein, such pressures may represent absolutepressure values or pressure values relative to a reference point, suchas atmospheric pressure, as those skilled in the art will recognize.

Aspects of exemplary implementations disclosed herein are intended to becapable of combination, separation, and exchange with other aspects ofexemplary implementations disclosed herein, except where expresslystated otherwise.

While the method and apparatus have been described in terms of what arepresently considered to be the most practical and preferred exemplaryimplementations, it is to be understood that the disclosure need not belimited to the disclosed exemplary implementations. It is intended tocover various modifications and similar arrangements included within thespirit and scope of the claims, the scope of which should be accordedthe broadest interpretation so as to encompass all such modificationsand similar structures. The present disclosure includes any and allexemplary implementations of the following claims.

It should also be understood that a variety of changes may be madewithout departing from the essence of the invention. Such changes arealso implicitly included in the description. They still fall within thescope of this invention. It should be understood that this disclosure isintended to yield a patent covering numerous aspects of the inventionboth independently and as an overall system and in both method andapparatus modes.

Further, each of the various elements of the invention and claims mayalso be achieved in a variety of manners. This disclosure should beunderstood to encompass each such variation, be it a variation of anexemplary implementation of any apparatus exemplary implementation, amethod or process exemplary implementation, or even merely a variationof any element of these.

Particularly, it should be understood that as the disclosure relates toelements of the invention, the words for each element may be expressedby equivalent apparatus terms or method terms—even if only the functionor result is the same.

Such equivalent, broader, or even more generic terms should beconsidered to be encompassed in the description of each element oraction. Such terms can be substituted where desired to make explicit theimplicitly broad coverage to which this invention is entitled.

It should be understood that all actions may be expressed as a means fortaking that action or as an element which causes that action.

Similarly, each physical element disclosed should be understood toencompass a disclosure of the action which that physical elementfacilitates.

Any patents, publications, or other references mentioned in thisapplication for patent are hereby incorporated by reference. Inaddition, as to each term used it should be understood that unless itsutilization in this application is inconsistent with suchinterpretation, common dictionary definitions should be understood asincorporated for each term and all definitions, alternative terms, andsynonyms such as contained in at least one of a standard technicaldictionary recognized by artisans and the Random House Webster'sUnabridged Dictionary, latest edition are hereby incorporated byreference.

Finally, all referenced listed in the Information Disclosure Statementor other information statement filed with the application are herebyappended and hereby incorporated by reference; however, as to each ofthe above, to the extent that such information or statementsincorporated by reference might be considered inconsistent with thepatenting of this/these invention(s), such statements are expressly notto be considered as made by the applicant(s).

In this regard it should be understood that for practical reasons and soas to avoid adding potentially hundreds of claims, the applicant haspresented claims with initial dependencies only.

Support should be understood to exist to the degree required under newmatter laws—including but not limited to United States Patent Law 35 USC132 or other such laws—to permit the addition of any of the variousdependencies or other elements presented under one independent claim orconcept as dependencies or elements under any other independent claim orconcept.

To the extent that insubstantial substitutes are made, to the extentthat the applicant did not in fact draft any claim so as to literallyencompass any particular exemplary implementation, and to the extentotherwise applicable, the applicant should not be understood to have inany way intended to or actually relinquished such coverage as theapplicant simply may not have been able to anticipate all eventualities;one skilled in the art, should not be reasonably expected to havedrafted a claim that would have literally encompassed such alternativeexemplary implementations.

Further, the use of the transitional phrase “comprising” is used tomaintain the “open-end” claims herein, according to traditional claiminterpretation. Thus, unless the context requires otherwise, it shouldbe understood that the term “compromise” or variations such as“comprises” or “comprising”, are intended to imply the inclusion of astated element or step or group of elements or steps but not theexclusion of any other element or step or group of elements or steps.

Such terms should be interpreted in their most expansive forms so as toafford the applicant the broadest coverage legally permissible.

What is claimed is:
 1. A system for mitigating leaks, comprising: afluid source; an injector; a regulator disposed between the fluid sourceand the injector; a system isolation valve disposed between theregulator and the injector; a first line connecting the fluid source tothe regulator; a second line connecting the regulator to the systemisolation valve, the second line having a second volume; a bleed valvefluidly connecting a pressure relief valve to the second line; a thirdline connecting the system isolation valve to the injector, the thirdline having a third volume; wherein the combined second volume and thirdvolume is configured to reduce an initial pressure of a fluid in thefirst line to a distribution pressure when the system isolation valve isopened; wherein the system isolation valve is configured to open if thedistribution pressure is equal to a target pressure for the injector;and, wherein the pressure relief valve is configured to vent the fluidin the second line if the bleed valve is open.
 2. The system of claim 1,wherein the fluid source is a storage tank having a tank valve.
 3. Thesystem of claim 1, wherein the distribution pressure is defined as apressure resulting from a substantially even distribution of the fluidin the second line across the combined volume of the second line and thethird line.
 4. The system of claim 1, wherein the injector is disposedbetween the second line and a fuel cell.
 5. The system of claim 1,further comprising a low pressure sensor configured to sense thepressure in the second line.
 6. A system for mitigating leaks,comprising: a fluid source; an injector; a regulator disposed betweenthe fluid source and the injector; a system isolation valve disposedbetween the regulator and the injector; a first line connecting thefluid source to the regulator; a second line connecting the regulator tothe system isolation valve, the second line having a second volume; ableed valve fluidly connecting a pressure relief valve to the secondline; a third line connecting the system isolation valve to theinjector, the third line having a third volume; wherein the pressurerelief valve is configured to release pressure in the second line, basedupon a ratio of the second volume to the third volume, if the pressureexceeds a predetermined value; and wherein the pressure relief valve isconfigured to vent the fluid in the second line if the bleed valve isopen.
 7. A system for mitigating leaks, comprising: a fluid source; aninjector; a regulator disposed between the fluid source and theinjector; a system isolation valve disposed between the regulator andthe injector; a first line connecting the fluid source to the regulator;a second line connecting the regulator to the system isolation valve,the second line having a second volume; a bleed valve fluidly connectinga pressure relief valve to the second line; a third line connecting thesystem isolation valve to the injector, the third line having a thirdvolume; and wherein the system isolation valve is configured to open anddistribute pressure in the second line, based upon a ratio of the secondvolume to the third volume, across the second line and third line whenthe pressure in the second line is less than a predetermined value.